Compared with petroleum distillates, residual fuel oil is a cheap fuel and it would be desirable to use it to fuel gas turbines. However, residual fuel oil, as well as crude oil, contains from about ten to several hundred parts per million vanadium, which is a significant contaminant. Vanadium is considered a contaminant since it has a highly deleterious corrosive effect on gas turbine components. Accordingly, it is necessary to remove vanadium from the residual fuel oil before it can be used in gas turbines.
Adsorption can be an easy and inexpensive method for removing trace contaminants from liquids. U.S. Pat. No. 4,513,093 to Beck et al. discloses a kaolin clay sorbent containing a metal additive to immobilize vanadium compounds. However, the adsorption process is operated at high temperatures (above 900° F.), which makes this approach costly and hazardous.
What is needed is a low cost and effective method for removing vanadium compounds from residual fuel oil at moderate temperatures.